Heavy-Duty Diesel Pickup Comparison Test

Heavy-duty diesel pickup trucks are the strongmen of the automotive world. These mammoth machines can tow hulking trailers so massive and carry payloads so crippling—they make lesser trucks slap the mat and tap out. If there's a commercial-duty job to be done in America, these trucks have the tools to do it.

And that work has become that much more grueling recently too, thanks to the ballooning weight of ever-larger fifth-wheel RVs, toy haulers and horse trailers. Tighter emissions regulations this year, that require a steep reduction in oxides of nitrogen, have made more work for the manufacturers too. So to answer the call, today's heavy-duty pickups now pack more powerful, more efficient and, yes, cleaner diesel engines, along with a stouter chassis underneath their bodywork and more features designed to make even the most laborious tasks seem like a Sunday drive.

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The pickup truck is rebounding right now, with nearly every manufacturer showing double-digit growth over last year. And heavy-duty pickup sales appear even stronger—in Ford's case, Super Duty sales are up an astonishing 58 percent in the first six months of 2010 over last year. New trucks certainly help. Just last fall, Dodge launched a new Heavy Duty Ram. And this year both the Ford Super Duty and Chevrolet Silverado/GMC Sierra HD pickups have been redesigned with new or improved diesels generating more than 700 lb-ft of torque.

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It's a good time to be a diesel fan.

So with a renewed optimism for the American pickup truck and freshly redesigned rigs in the marketplace, it was time to find out how these Motor City big boys stack up. We gathered three-quarter-ton 4WD crew-cab diesel pickups from Ford, Dodge and GMC and put them through an exhaustive weeklong Michigan test regimen.

We spent two days measuring the performance of these trucks at Chrysler's Chelsea Proving Grounds both unloaded and burdened with a 10,000-pound test trailer. True, some light-duty trucks are rated to haul a maximum load that heavy. But if serious towing were a part of the regular duty cycle, we'd certainly favor a diesel pickup.

Later, we piled on more than 400 miles with our trio over varied terrain ranging from the mean streets of downtown Detroit to the country lanes, highways and dirt back roads of rural Washtenaw County to test the fuel economy of these rigs. When the dust settled and the numbers were crunched, we had our favorite workhorse.

Third Place: Dodge Ram 2500 Laramie Crew Cab 4x4

There's a heavy-hauler authenticity to a Dodge Ram powered by a Cummins diesel. Fire up the 350-hp 6.7-liter inline six and you can feel the heft and torque of this overbuilt, 1300-pound engine as you prod the throttle. It feels and sounds more "big rig" than the other two in this test. A version of the B-Series Cummins inline six has lived under the hood of every diesel Dodge pickup for the last 21 years. The reputation is legendary, and that builds serious loyalty. However, the Cummins's 650 lb-ft of torque is down by 85 lb-ft to the Ford and by more than 100 lb-ft to the GMC. And so our $55,150 Ram trailed the other two in every speed contest and delivered fewer miles per gallon too.

Though the Dodge was slower than the other two, it was more adept at slowing a load—without using the left pedal. The Dodge's exhaust brake felt more powerful than those in the other two trucks on both our 7 percent and 15 percent grade evaluations. That means you can ease off the throttle with a heavy load and let the exhaust brake slow the rig—saving your brakes.

But the Dodge has a hidden advantage when it comes to servicing. The 6.7-liter Cummins met today's tough emissions standard early—back in 2007—and did so without the use of diesel exhaust fluid (DEF), at about $2.75 a gallon. Instead, Dodge uses a nitrogen-oxide-absorber catalyst. The upside for the truck owner? You won't have those scheduled emissions-related service costs.

The Dodge's bodywork was new for the 2010 model year but the basic bones of the chassis date back to 2007. That resulted in a ride that was noticeably rougher and less sophisticated than the other two. Strapped to our test trailer, the Dodge required more steering correction than the others on the highway. And we were surprised that this truck isn't available with the security of traction or stability control systems.

Slide into either of the Ram's front seats, or the rear ones for that matter, and you'll find better all-day comfort than in the other trucks. And like the Ford, our Ram had both heated and cooled seats—an option we would certainly order on our own truck. The interior of our Laramie's dash is trimmed in soft-touch material that looked very upscale. This Ram's interior was the most luxurious of all the trucks here.

Pampering aside, the Dodge is, in many ways, an honest old-school work truck. It's a trait we can appreciate. But in this group, its level of civility, power and chassis refinement felt a half-step behind the competition.

Second Place: GMC Sierra 2500HD 4WD Crew Cab SLT

One would never mistake a nearly 4-ton diesel pickup for a muscle car. But in this group, the $59,150 GMC could just as easily have had a Z/28 badge plastered on its flanks—it was quick, hitting 60 mph in under 8 seconds. Credit the reworked Duramax diesel, which developed 367 hp and a Kenworth-crumbling 765 lb-ft of torque. Oh, and the GMC provided the best unladen fuel economy—nearly 18 mpg. Not bad for a 7700-pound truck. GM says it can travel upwards of 680 miles on its 36-gallon tank, if you're easy on the throttle. To meet the 2011 diesel emissions standard, the GMC uses a urea-based DEF housed in a 5.3-gallon tank that must be refueled approximately every 5000 miles. And GM provides several warning messages as the fluid is used up.

The Sierra's bodywork may look just like last year's model, but under the skin, there's a new fully boxed frame, suspension and independent front suspension that's built to carry 25 percent more weight than last year's truck. When the road started to bend, the GMC's retuned suspension and our model's blingy 20-inch wheels and low-profile tires helped it handle more like a light-duty truck, with the most precise steering of the group. On rougher roads around Michigan with the bed empty, the GMC generally delivered a bumpier ride than the soft Ford but a smoother one than the Dodge. And on the deepest and sharpest impacts, the GMC actually bucked harder in the rear than either one.

Out on the open highway the GMC's mammoth motor provided easy cruising and ridiculously effortless passing power. Unlike the Dodge and the Ford, the GMC's dash has a low cowl for excellent visibility, and the interior is a carbon copy of the ones used in light-duty pickups and SUVS. The interior is very car-like, and that helps the GMC drive smaller than it actually is.

Hitched to a trailer, the GMC was more than a second quicker to 60 mph than the Ford and more than 4 seconds sprightlier than the Dodge. That, folks, is significant. On our informal 15 percent grade test, however, the Ford edged out the GMC. On bumpy roads with that trailer, the Sierra's ride nearly equaled that of the Ford, and the setup felt exceedingly stable at freeway speeds. With one push of the dash-mounted button, the GMC's exhaust brake and the Allison transmission's nearly telepathic downshifts helped slow our load on steeper grades without relying on those massive 14-inch disc brakes too much. Used as a passenger hauler the GMC's rear seat has contours not unlike a bucket seat but offering less comfort than the Dodge's.

The GMC was very close to taking the gold medal in this test. Its potent and efficient powertrain and sharp handling make the Sierra HD easy to fall for. But it was the Ford's mix of work-focused options and class-leading comfort that nudged it over the top.

First Place: Ford F-250 Lariat Crew Cab 4x4

The Ford's menacing chrome-plated maw and husky big-rig styling make it look like an Autobot on the set of Transformers 3. Over-the-top machismo? Perhaps. But the beauty of this $59,475 Ford has nothing to do with its styling. As butch as it might look, this heavy hauler is really just about as good-natured and easy to live with as an F-150. The ride quality of our 7800-pound Lariat was incredibly smooth over any terrain. It not only rides better than any truck here, the new Super Duty glides over broken pavement better than some light-duty trucks. And that's surprising, considering the Duty still uses beefy solid axles at each end of the chassis. The secret? According to Chief Engineer Chris Brewer, eliminating two leaves from the rear spring packs along with re-tuned shocks. Equally impressive is the steering, which one could twirl from lock to lock with all the muscle of a single finger. Yes, some testers prefer steering with a bit more heft. But the usefulness of the featherweight effort was evident in both the tight city parking spaces and when backing our trailers—it's a real fatigue fighter. On the highway that steering does have a large dead spot on center, but, hey, this is a pickup truck, not a Porsche.

Ford's outgoing, and outsourced, 6.4-liter Power Stroke was plagued with poor reliability. So Ford brought the operation in-house and created an all-new 6.7-liter V8 with a beastly 390 hp and 735 lb-ft of torque paired to a new 6-speed automatic. To meet the 2011 emissions requirement the Ford uses a 6-gallon urea diesel exhaust fluid tank that can last up to 7500 miles between fill-ups.

The new Power Stroke certainly packs a wallop, but at the track, the Super Duty ran a truck length or two behind the GMC in just about every speed contest. Yet away from the stopwatch, the two feel more evenly matched than the numbers suggest. The Ford's throttle response is razor sharp and the torque is nearly instant on. Better still, the Ford's diesel was the quietest of the three at full throttle, at idle or on the highway. Trailer in tow, we evaluated each pickup on a 15 percent hill gradient test. The Ford maintained a higher speed at the crest of that hill than any truck here. And on our towing fuel-economy loop, the Ford was thriftiest too.

Slide behind the Ford's big steering wheel and it feels like you've got a command center at your fingertips. The dash is expansive and useful with toggle switches ready to be wired up to your favorite accessories. The center console packs a hidden compartment and is reconfigurable to accommodate just about anything. And we dug the new Productivity Screen, a customizable system that provides checklists ranging from trailer and off-road setups to fuel-economy performance and the temperature of vital components. Smart. Flip up the rear seat and there's a handy lockable storage bin. And like Super Duties of the past, our truck came with unique features like the handy tailgate step, power extendable towing mirrors and even an electrically locking rear differential.

The new Super Duty may not be the quickest here, but a truck is more than just a motor. And it was the Ford's unmatched mix of comfort and smart, work-friendly features that helped it edge out the competition. There's a reason Ford owns 50 percent of the heavy-duty truck market.